1. Field of the Invention
The present invention relates to a synchronizing signal extracting apparatus for use in a digital signal recording/reproducing apparatus and the like.
2. Description of the Related Art
A digital audio tape recorder (DAT) and a digital video tape recorder (digital VTR) are known as digital signal recording/reproducing apparatuses. In these digital signal recording/reproducing apparatuses, a digitized video signal or audio signal is added with a synchronizing signal, an identification code, and an error correction code at each predetermined interval to form a sync block before being recorded. At reproduction, the synchronizing signal is detected to determine a head of the sync block to perform such processing as error correction and digital/analog conversion.
In the DAT, the synchronizing signal is extracted only by means of matching patterns of one byte constituting the synchronizing signal and checking a simple parity.
However, the above-mentioned method in which the synchronizing signal is extracted only by pattern matching and simple-parity checking is unable to extract a correct synchronizing signal when missed detection or erroneous detection occurs.